西太平洋低频振荡强度的年际变化及其主模态特征  

Interannual Variation of Low Frequency Oscillation Intensity and its Main Modal Characteristics in the Western Pacific Ocean

作　　者：陈沛宇 侯劭禹 巩远发[3] 付娇 赵福虎 刘成瀚 王焕哲 CHEN Peiyu;HOU Shaoyu;GONG Yuanfa;FU Jiao;ZHAO Fuhu;LIU Chenghan;WANG Huanzhe(Meteorology Technical Equipment Center,Shijiazhuang 050021,China;Hebei Weather Modification Office,Shijiazhuang,050021,China;College of Atmospheric Sciences,Chengdu University of InformationTechnology,Chengdu 610225,China;Chongqing Meteorological Observatory,Chongqing 401147,China;Liaoning Meteorological Observatory,Shenyang 110166,China)

机构地区：[1]河北省气象技术装备中心,河北石家庄050021 [2]河北省人工影响天气办公室,河北石家庄050021 [3]成都信息工程大学大气科学学院,四川成都610225 [4]重庆市气象台,重庆401147 [5]辽宁省气象台,辽宁沈阳110166

出　　处：《成都信息工程大学学报》2022年第1期96-102,共7页Journal of Chengdu University of Information Technology

基　　金：国家自然科学基金资助项目(41775079);国家自然科学基金重点项目——区域创新发展联合基金资助项目(L20A2097)。

摘　　要：为研究南海-西太平洋OLR 30~60天低频振荡时空变化的主模态及其对中国夏季降水的影响,利用逐日向外长波辐射(OLR)和中国839站降水资料,采用带通滤波、EOF和线性回归等方法,分析南海-西太平洋OLR30~60天低频振荡强度的季节分布和时空变化特征及其与中国夏季降水距平之间的联系。结果表明:(1)西太平洋地区OLR 30~60天低频振荡强度及其空间分布都具有显著的季节变化特征,活跃区主体基本位于南北半球的低纬热带海域。(2)EOF第一模态特征向量在冬、春两季的最大变率中心主要在南半球赤道附近低纬地区,夏、秋两季北移至北半球低纬地区;EOF第二模态特征向量出现了经向三极子型和三角形三极子型分布。(3)部分地区的夏季降水异常与西太平洋季风和副热带季风、南海季风的强度存在一定的相关性。对比两次线性回归结果,发现夏季热带西太平洋OLR 30~60天低频振荡强度的第二模态与长江中下游降水有较好的联系,表明夏季长江中下游降水受副热带季风、南海季风的影响较大。In order to study the main mode of the spatio-temporal variation of the 30-60 day low-frequency oscillation in the South China Sea-Western Pacific and its influence on summer precipitation in China,the daily Outgoing Long-wave Radiation(OLR) and precipitation data from 839 weather stations in China are used.The seasonal distribution and spatiotemporal variation characteristics of the 30-60 day low-frequency oscillation intensity in the South China Sea-Western Pacific and its relationship with summer precipitation anomalies in China are analyzed by means of band-pass filtering,EOF and linear regression.Results show that:(1) the intensity and spatial distribution of OLR 30-60 day low frequency oscillation in the Western Pacific have significant seasonal variation characteristics,and the main active areas are mainly located in the low-latitude tropical waters of the northern and southern hemispheres.(2) the maximum variability center of the first mode characteristic vector of EOF in winter and spring is mainly in the low latitudes near the equator in the southern hemisphere,and moves northward to the low latitudes in the northern hemisphere in summer and autumn.The second modal eigenvector of EOF shows meridional tripole distribution and triangular tripole distribution.(3) Summer precipitation anomalies in some areas are related to the intensity of the Western Pacific Monsoon,Subtropical Monsoon,and South China Sea Monsoon.Comparing the two linear regression results,it is found that the second mode of the OLR 30-60 low frequency oscillation intensity in the tropical Western Pacific in summer has a good relationship with the precipitation in the middle and lower reaches of the Yangtze River,indicating that the summer precipitation in the middle and lower reaches of the Yangtze River is greatly affected by the subtropical monsoon and the South China Sea monsoon.

关 键 词：气候学 低频振荡强度 射出长波辐射 西太平洋 长江中下游 

分 类 号：P447[天文地球—大气科学及气象学]